Heater system



J. W. F. MACDONALD.

HEATER SYSTEM.

APPLICATION FILED 020.5. 1918.

1,437, 1 7, Patented Nov. 28, 1922. I

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-. N1 D sTATEs Patented Nov, 28, 1922.

JOHN W. F M ACD ONALD', OF BRIGHTON, MASSACHUSETTS, ASSIGNQR TO THE -MERRILL PROCESS COMPANY, A CORPORATION E MASSACHUSETTS. v

HEATER SYSTEM.

Application filed December 5, 1918. Serial No. 265,385.

To all whom it concern:

Be it known that I JOHN W. Mac- I DONALD, a citizen of the United States, and

the typedisclosed in my a resident of Brighton, in the county of Suffolk and State of Massachusetts, have invented an Improved Heater System, of which the following is a specification, reference being had to the accompanying drawinqs, forming part'thereof.

This invention has reference to an provement in the class of heating systems of prior Patent No. 1,278,067 granted September ,3, 1918, in

" which a .heat absorbing oily liquid is me- ;chanically circulated through a continuous,

conduit having a point of heat utilization 3 or radiation and a point of heat absorption.

suction sideof which deficienciesin volume from an expansion'pipe.

"At such point of radiation said liquid may contract somewhat through loss ofheat after which said liquid passes to a pump at the supply of liquid In the passage of are compensated for by, a

' said liquid through the pump it is subjected to the mechanical pressure of said pump and passes to theheating point under said pressure. At such heatingpoint said liquid is subjected to a high temperature and as globules or-bubbles tend to expand and such expansion is increased by the pressure of any air or humidity present in the conduit by reason of condensation or by water or air inadvertently entering with the supply of .oil from theexpansion pipe.

The main ob'ect of this invention is to provide a vent for theescape of air, water or as of any kind from the circulating liquid of systems ofthis nature approximately at the time when said liquid is at its greatest expansion and is under pressure of the circulatingpump. That is, air, moisture or other gas inadvertently enteringthe conduit from the expansiontank or present in liquid in such, conduit at the heating point shouldbe eliminated or, at least, allowed to escape before such air, moisture, etc., causes an undueor possibly dangerous expansion of the circulatingliquid.

, The invention consists in the novel 'features of constructionand' combination of parts as shall hereinafter be more fully described and pointed outin the claims.

The drawing represents a view in elevation of a heating system of the nature herein referred to and illustrating the new improvement. 7

As shown in the drawing5 indicates a furnace of any known construction having ,the coil conduit 6 of any well known kind 'adaptedto direct the flow of liquid passing therethrough tofacilitate the absorption by said liquid of heat supplied to said furnace. At a distance from said furnace coil 6 is located the radiator conduit 7 which is the point or device at-which the heat absorbed by the liquid in passing through the coil 6 is utilized. Such liquid is conveyed from the coil an) the coil 7 by an upper supply conduit '8 and after the heat of said liquid has been wholly or partially utilized-in said coil 7 said liquid is returned to coil 6 through a lower return conduit 9.

The system, therefore, comprises in circuit a heater, a heat utilizing means, a supply conduit leading from said heater to said heat utilizing means, and a return conduit leading from the latter to the heater, all of tion 9 of the conduit, said pump subjects the cooler, and somewhat condensed, liquid to a suflicient mechanical pressure to maintain a free circulation thereof toward the heater. The action of the pump also causes the free circulation of the heated liquid from the heater to the radiator or other heat utilizing means.

In order to compensate for the fluctuations I of the liquid in the return conduit 9 by the suction of the pump, and to maintain a static pressure upon the liquid throughout the entire circulating system, the conduit 9 is provided at apoint preferably near the suction end of the pump 10 with a pipe 11 which communicates at its upper end with an expansion tank 12 preferably located at a higher level than the supply conduit 8.

The supply conduit 8 is provided with a' branch or'vent pipe 13 which extends upwardly and communicates with the upper end of the expansion tank 12, and is adapted liquid may be by-passed from the supply conduit Slinto the expansion tank. The union which connects the supply conduit 8 with the branch or vent pipe 13 desirably is of considerably greater diameter than that of the conduit 8 and forms a chamber or trap 8" for the air or gas which is contained in the circulating fluid.

It has been found in starting a newly installed system of this nature that-the liquid with which the conduit system is filled contains considerable air, moisture and accumulations of liquid of a more volatile nature than the main body of liquid. Under heat, such air, moisture and more volatile liquid expand andoften cause undue expansion of the main liquid which reduces the efliciency of the system, particularly the pump. In practice it is found that in startng a newsystem the valve 14 of branch or vent pipe 13 may be left open for the es cape of air, steam or other gas for a considerable period, sometimes for several days, without permitting the escape of any material amount of the viscous circulating liquid through such pipe 13 of small diameter.

When the system is out of operation, as forv instance, overnight, the mechanical circulation of the viscous liquid ceases and the temperature of said liquid usually is re duced whereby said liquid may contract or become somewhat condensed. In such variations in the density of the li uid and possibly for other reasons, bub les are formed in the liquid and small amounts of air or water find their way into the body of the liquid, and other" impurities. contained in said liquid may coalesce to an objectionable extent. It is of course desirable to discharge such air or gas and other impurities from the liquid particularly atthe starting of the system or soon'thereafter.

.Without considering specific details of the operation of the system it may be observed that the application of heat to the coil .6 effects a rise in temperature of the liquid contained in said coil and a rmulta-nt expansion of said liquid and particularly of the moisture, air or other'ga's contamed therein whereby if a vent is opened said moisture, air 01:. other gas with the bubbles or globules of liquid containing said moisture will tend to escape through said vent. The operation of pump 10 forces the liquid in return conduit 9 towards and through the coil 6 from whichthe heated passes by the vent pipe 13 through which, if valve 14: is open, the more volatile or lighter portions of gas escape, passing upward through said pipe 13 and ultimately reaching the ,expansion tank 12. The heavier or more viscous liquid circulates through said supply wnduit 8 to and through the radiator coil 7 and thence through the return conduit 9 to the pump 10 and may, through loss of heat, again contract or condense and sometimes permit the formation of additional bubbles. At or about the time such liquid reaches the suction side of pump 10, the fluctuations in density and volume of said liquid are, to a large extent compensated for by liquid from the expansion pipe which liquid is under static pressure.

By locating'the outlet of vent pipe 13 at a considerably higher point than the inlet tosaid pipe 13 from the conduit arm 8 and making said vent pipe considerably smaller than conduit arm 8 resistance is provided to the passage of the main body of viscous liquid through said pipe 13.

Having thus described my invention I claim as new and desire to secure by Letters Patent.

1. A heating apparatus fortransporting heat by. means of a traveling body of viscous material maintained at a temperature below its boiling point, comprising in a circuit a heater, a heat utilizing means, a supply conduit leading from said heater tosaid heat utilizing means, a return conduit leading from said heat utilizing means to said heater, a pump in the return conduit acting to circulate the liquid in said conduit toward said heater, an expansion tank located at a higher level than said supply conduit, means for delivering liquid from said expansion tank to the return conduit upon the intake side of said pump adapted to maintain a constant static pressure upon the liquid-throughout the circuit, a chamher in said supply conduit adapted to-trap and separate gaseous impurities or products from the circulating liquid and a vent pipe communicating with the upper portion of said chamber to permit the'escape of such gaseous impurities or products.

2. A heating ap aratus, for transporting heat by means. 0 a travelling body of viscous liquid maintained at a temperature below its boiling point, comprising in circuit a heater, a heat utilizing means, a supply conduit leading from said heater to said heat utilizing means and a return conduit leading from the latter to said heater, mechanically operated means for circulating the liquid in the return'conduit towards said heater an ex ansion, tank, means for delivering hquld t erefrom to said return conduit between said heat utilizing meansand said circulating means adapted to maintain a static pressure on said liquid throughout the circuit, a chamber in said supply conduit adapted to separate gaseous 1mpurities or products from the circulating liquid, and a branch pipe connecting said chamber with said expansion tank, and a valve in said branch pipe operable either to permit the delivery of the gaseous impurities and a portion of the liquid circulating through said supply conduit to said expan- 10 sion tank or to confine the circulating fluid to said conduit 1 J OHN W. F. MACDONALD. 

